Model error apparent when uv uwrapping. How can I locate and delete errant faces?
Thank you to Mr Zak for his comment and solution.

By using the Keep UV and Edit mode selection in sync button in the UV editor ( its the one approx centre that looks a bit like a Pac Man eating a mouse pointer arrow) selected I was able to then select the two errant faces in the UV map and have them shown in the 3d view.

This confirmed that they were modelling errors, rather than say miss-aligned vertices, and I was then able to delete them.

Co-incidentally it also showed up a corner where the vertices were non-aligned rather than connected correctly. A very useful little button...